Novel crispr enzymes and systems

A method of detecting target nucleic acids in one or more samples, the method comprising:

• contacting the one or more samples with a Type VI Cas polypeptide and a guide molecule, wherein the guide molecule is capable of forming a complex with a Type VI Cas polypeptide and directing the binding of the complex to a target nucleic acid, wherein the Type VI Cas polypeptide exhibits collateral RNAse activity upon binding to the target nucleic acid;
• and
• detecting degradation of non-target nucleic acids indicates the presence of the target nucleic acid in the sample.

A plant cell modified to express a Type VI Cas polypeptide, one or more guide molecules capable of forming a complex with the Type VI Cas polypeptide, or both.

A method of modifying a plant, the method comprising:

• delivering to a plant cell originating from the plant, a Type VI Cas polypeptide and one or more guide molecules, wherein the one or more guide molecules are capable of directing sequence-specific binding of the complex to one or more target polynucleotides in the plant cell.

A composition comprising a Type VI Cas polypeptide and one or more guide molecules, wherein the one or more guide molecules are capable of forming a complex with the Type VI Cas polypeptide and direct sequence-specific binding to one or more target viral polynucleotides.